Telephone system



B. s. COHEN.

TELEPHONE SYSTEM.

F\P PLICAT|0N FILED DEC. 3h I919.

Patented June 14, 1921.

UNITED STATESPATENT OFFICE.

.BERTRAM SYDNEY coHEN, or 'rwIcKENHAM, ENGLAND, ASSIGNOR TO THE nEn y AUTOMATIC TELEPHONE comranr LIMITED, or STRAND, ENGLAND,

TELEPHONE SYSTEM.

To all whom it may concern:

Be it known that I, BERTRAM SYDNEY COHEN, a subject of the King of Great Britain, residing at 9 Lebanon Park, Twickenham, 'Middlesex, England, have invented a new and useful Improvement in or Relating to Telephone-Systems, of which the following is a specification.

The object of this invention is to pro vide apparatus whereby telephonic communication between two stations ordinarily con nected by metallic out and return leads may be maintained when one of the leads is broken.

-The apparatus is primarily intended for use in kite balloon telephone circuits which ordinarily consist of a metallic holding cable forming-one lead and a metallic core forming the other lead.

It is found in practice that the core frequently breaks and the apparatus forming the subject matter of this invention has been devised with the primary view of maintaining telephonic communication through a circult comprising the metallic holding cable and a condenser formed by metal work attached to the balloon basket and the earth.

The invention is illustrated by the accompanying diagrammatic drawing which shows the connections for a kite balloon telephonic installation.

A, B, C, are three windings of a transformer, winding A being connected in series with a transmitter D and battery E, while winding 13 is connected to a receiver F; one end of the winding C is connected to a ca pacity G which may consist of metal work forming part of or attached to a balloon basket and the other end of the winding C is connected to one contact of a switch H, the other contact of which is connected to the transmitter and receiver. I, J, are two conductors connecting the parts'already mentioned to a distant station at which there is a transformer having three windings a, b, a, Winding a being connected in series with a transmitter d and battery 6, and winding 1) being connected in series with a receiver 7'. h is a switch by which the end of the conductor I incoming to the last named apparatus can be connected to the receiver 7 and transmitter d either conductively or inductively through the third winding 0 which is connected to earth. The conductor I may be a metallic cable holding the kite balloon,

Specification of Letters Patent.

' Application filed December 31, 1919.

Patented June 14, 1921. Serial Nol 348,631.

while dis a conductor which may form the core of the cable. Normally the arm of the switch H is moved to the left and {the arm Of SWltC ll hismoved to the right, so that the third wlndlngs C, c, are not employed, but should conductor J for any reason be inoperat ve the arm of switch H is moved on to ltS right hand contact and the arm of switch it s moved on to its left hand contact, thus bringing into circuit the third windings of the transformersand the condenser formed by the capacity G and the earth.

In order to obtain the best terminal conditions and consequently the highest efficiency the number of turns of the third windmg C is larger than that in the winding 0.

IVhat I claim is f- 1, In a telephone installation, the combination of a transmitter, areceiver, a capacity, a transformer having three windings, one in series with the transmitter, the second in series with the receiver and the third con nected at one end to the capacity, a pair of conductors, one being connected to the transmitter and receiver, and means for connecting the other conductor either to the transmitter and receiver or to the other end of the third winding of the transformer.

2. In a telephone installation, the combination of a transmitter, a receiver, a capacity, a transformer having three windings, the first in series with the transmitter, the second in series with the receiver and the third connected at one end to the capacity, all at one station, and at a distant station a transmitter, a receiver, and a transformer having three windings, the first in series with the transmitter, the second in series with the receiver, and the third connected to earth, two conductors connecting the two stations, one being connected to the transmitter and receiver at each station, means at the first station adapted to connect the other conductor to the transmitter and receiver or to the third winding and means at the second station for connecting the last named conductor to the transmitter and receiver of that station or to the third winding of the transformer.

3. In a telephone installation, the combination of a transmitter, a receiver, a capacity, a transformer having three windings, the first in series with the transmitter, the second in series with the receiver and the third connected at one end to the capacity, all at one station, and at a distant station a transmitter, a receiver, and a transformer having three windings, the first in series with the transmitter, the second in series with the receiver, and the third c0nnected to earth, the number of turns in the third winding of this transformer being less than that of the turns in the transformer at the first station, two conductors connecting the two stations, one being connected to the transmitter and receiver at each station, means at the first station adapted to connect the other conductor to the transmitter and receiver or to the third winding and means at the second station for connecting the last named conductor to the transmitter and receiver of that station or to the third winding of the transformer.

4c. In a telephone installation, the combinationof a transmitter, a receiver, a capacity, a transformer having three windings, the first in series with the transmitter, the second in series with the receiver and the third connected at one end to the capacity, all at one station, and at a distant station a transmitter, a receiver, and a transformer having three windings, the first in series with the transmitter, the second in series with the'receiver, and the third connected to earth, a metallic cable and a conductor both extending between, the stations, the conductor being connected to the transmitter and receiver at each station, means at the first station adapted to connect the cable to the transmitter and receiver or to the third winding and means at the second station for connecting the cable to the transmitter and receiver of that" station or" to the third winding of the transformer.

5. In a telephone installation, the combination of a transmitter, a receiver, a capacity, a transformer having three windings, thefirst in series with the transmitter, the second in series with the receiver and the third connected at one end to the capacity, all at one station, and atga distant station a transmitter, a receiver, and a trans former having three windings, the first in series with the transmitter, the second in series with the receiver, and-the third connected to earth the number-of turns in the third winding of this transformer being less than that of the turns in the transformer at the first station, a metallic cable and a conductor both extendlng between the stations, the conductor being connected to'the transmitter and receiver at each station, means at the first station adapted to connect the cable to the transmitter and receiver'or to the third winding and means at the second station for connecting the cable to the transmitter and receiver of that station or to the third winding of the transformer, V v

In testimony that I claim the foregoing as my invention I have signed my name this eighth day of December, 1919.

BERTBAM SYDNEY ooHnnQ 

